Branichevists are a Slavic tribe on the middle Danube , in the territory of modern Serbia .
About 805, the lands of Branichevites became part of Bulgaria , after the capture by the troops of the Bulgarian Khan Krum of the eastern part of the Avar Kaganate . In 818, they revolted in the reign of Omurtag along with other border Slavic tribes, as they refused to accept the reform that limited their local self-government. In search of an ally, they turned to the Holy Roman Emperor Louis I the Pious . In the years 824 - 826, Omurtag tried to resolve the conflict through diplomatic means, but his letters to Louis remained unanswered. After that, he decided to crush the uprising by force and sent soldiers to the lands of the Danube Slavs, who again returned them to the rule of Bulgaria.